1. Field of the Invention
The present invention relates to a method for observing a fluid and a fluid for flow observation.
2. Description of the Related Art
Heretofore, particle image velocimetry (hereinafter referred to as PIV) has been used as a method for observing a fluid. Particle image velocimetry involves adding particles following the flow (tracer particles) to the fluid, irradiating the fluid with a pulsed laser beam to track the movement of the fluid, following the motion of the tracer particles with a video camera or the like, capturing images of the travel distance of the particles at sufficiently small time intervals on a flow time scale, and determining the distance and direction of the travel (see, for example, Japanese Unexamined Patent Application Publication No. 2003-84005).